GLM-5.3

Z.ai's 2026-08-14 coding model, pitched as the strongest open-weights coder on the market. At 743B parameters, it reuses the GLM-5.2 base model with all gains coming from expanded post-training ("more environments, more diverse tasks, more compute"), and keeps the 1M-token context and 128K output ceiling while consuming far fewer tokens per task. Live at launch through the GLM Coding Plan subscription and ZCode, with API access and downloadable weights following after a safety review (reported ~2 weeks out), so open weights are not yet available.